This invention relates to building construction and is particularly concerned with construction of buildings of reliable strength incorporating factory-produced reinforced concrete modular components.
Building construction systems which utilize precast concrete structural components have found widespread acceptance, partly because of their capacity for use in construction of relatively low-cost, strong and durable buildings. Many different types of prefabricated building parts and connectors have been proposed for interconnection in the process of erection of footings, floors, walls and ceilings buildings of a variety of uses.
Such prior art patents as Russian Patent 887,757, Hazelett, Jr. U.S. Pat. No. 3,996,714, Allan U.S. Pat. No. 4,606,165, Herbrick U.S. Pat. No. 1,394,550, Cox U.S. Pat. No. 3,898,776, and Waugh U.S. Pat. No. 2,091,061 describe various concrete panel structures and ways in which they can be interconnected as parts of buildings. Scott U.S. Pat. No. 3,733,757 discloses a building frame structure in which concrete members are interconnected by mechanical connectors.
Heller U.S. Pat. No. 4,126,978 and Herrgord U.S. Pat. No. 4,594,829 disclose systems for interconnecting the edges of panels for use, for example, as space dividers.
German Patent No. 935,454 discloses a building having small wall panels with tapered margins, interconnected by and held in place between vertical members by grooves defined by the vertical members to receive the tapered margins of the panels.
British Patent No. 10,840 discloses a prefabricated wooden structure utilizing columns defining vertical grooves for receiving the ends of wall panels. Footings include square sockets to receive the lower ends of such columns.
The prior art refers to the need for such construction processes as welding of connecting parts at the building site, where a certain level of skill is required of the technician to produce satisfactory welds without creating additional stress or deformation of the various parts. Skill among welders is known to vary greatly and quality control inspection as done on-site is at best spotty, sometimes impractical, and at other times virtually impossible. Therefore it is desirable to do as much as possible of such structural welding in a controlled factory environment, and then to fasten structurally related parts to one another mechanically at the building site. Factory quality-control supervision is also desirable to avoid the results of corrupt failure to enforce building codes.
One previously known practice employed to assemble and hold together precast concrete panels is the use of bolted-on steel tie plates, connecting vertical panels at their corners. Under stress of severe natural forces, however, such corner areas tend to shear off causing walls to collapse.
It is desirable, therefore, to be able to quickly erect a relatively low-cost building shell which is strong and durable, using prefabricated concrete panels which can be transported to the construction site. It is desirable for such a building to be able to be disassembled and reerected at a different location.
It is also very important that the structure erected of such components be able to withstand the various stresses to which it might be subjected, including those such as storm winds or earthquakes.
What is needed, then, is a building system for manufacturing low-cost buildings of predictable quality which can be rapidly assembled, and which, once assembled, are rigidly and securely unified into a structure capable of successfully resisting such extraordinary forces as those of storm winds and earthquakes as well as normal building loads.